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941.
Shidi Xun Quanguo Zhou Hongchao Li Dongge Ma Lixiang Wang Xiabin Jing Fosong Wang 《Journal of polymer science. Part A, Polymer chemistry》2008,46(5):1566-1576
Three series of poly(phenylene vinylene) (PPV) derivatives containing hole‐transporting triphenylamine derivatives [N‐(4‐octoxylphenyl)diphenylamine, N,N′‐di(4‐octyloxylphenyl)‐N,N′‐diphenyl‐1,4‐phenylenediamine, and N,N′‐di(4‐octoxylphenyl)‐N,N′‐diphenylbenzidine] (donor) and electron‐transporting oxadiazole unit (2,5‐diphenyl‐1,3,4‐oxadiazole) (acceptor) in the main chain were synthesized by improved Wittig copolymerization. The resulting donor–acceptor (D‐A) polymers are readily soluble in common organic solvents, such as chloroform, dichloroethane, THF, and toluene. The polymers containing oxadiazole group exhibit good thermal stability with 5% weight loss above 400 °C. The intramolecular charge‐transfer was observed in these D‐A polymers. In comparison with corresponding polymers without oxadiazole unit, the single‐layer devices based on the D‐A polymers showed much improved electroluminescent properties, because of the balanced charge injection and transport. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 1566–1576, 2008 相似文献
942.
Chun‐Guey Wu Hung‐Chieh Lu Liang‐Nien Chen Yung‐Chou Lin 《Journal of polymer science. Part A, Polymer chemistry》2008,46(5):1586-1597
Two new 1,10‐phenanthroline (Phen) containing conjugated oligomers, oligo‐3,8‐bis(4‐octylthiophene‐2‐yl)‐1,10‐phenanthroline) (PDTPh) and oligo‐3,8‐bis‐(4‐octyl‐5‐(4‐ctylthiophene‐2‐yl)thiophene‐2‐yl)‐1,10‐phenanthroline) (PTTPh), as well as their corresponding monomers (OTPhOT and OTOTPhOTOT) were prepared and their metal ion‐sensing properties were investigated. The oligomers showed high thermal stability, good proccessibility, and gave varied color when reacted with different metal ions. Oligomers also showed distinct responses toward metal ions when compared with their corresponding monomers, suggesting that the ionochromic responses were determined by not only the coordinating ability of Phen unit but also the conformation of oligomer chains. Moreover, the differences in the ion‐sensing behaviors between OTPhOT and OTOTPhOTOT also suggested that the coordination ability of Phen depends on its substituents. The oligo‐alkylthiophene moieties in PDTPh and PTTPh acted as spacers to reorganize the conformation of the oligomer chains, as well as the electron donating groups to adjust the coordination ability of the Phen. These findings provide a clue for designing Phen‐containing ion‐sensors for specified ion‐sensing applications. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 1586–1597, 2008 相似文献
943.
Anion recognition and sensing in organic and aqueous media using luminescent and colorimetric sensors 总被引:1,自引:0,他引:1
Thorfinnur Gunnlaugsson Mark Glynn Gillian M. Tocci Paul E. Kruger Frederick M. Pfeffer 《Coordination chemistry reviews》2006,250(23-24):3094
This review article focuses primarily on the work carried in our laboratories over the last few years using luminescent and colorimetric sensors, where the anion recognition occurs through hydrogen bonding in organic or aqueous solvents. This review begins with the story of the discovery of fluorescent photoinduced electron transfer (PET) sensors for anions using charged neutral urea or thiourea receptors where both fluorescent and NMR spectroscopic methods monitored anion recognition. This work led to the development of dual luminescent and colorimetric anion sensors based on the use of the ICT based naphthalimide chromophore, where ions such as fluoride gave rise to changes in both the fluorescence and the absorption spectra of the sensors, but at different concentrations. Here, the former changes were due to hydrogen bonding interactions, whereas the latter was due to the deprotonation of acidic protons, giving rise to the formation of the bifluoride anion (HF2−). Modification of the 4-amino-l,8-naphthalimide moiety has facilitated the formation of colorimetric anion sensors that work both in organic or aqueous solutions. Such charge neutral receptor motifs have also been incorporated into organic scaffolds with norbomyl and calixarene backbones, which have enabled us to produce anion directed self-assembled structures. 相似文献
944.
L. Trinkler B. Berzina M. Benabdesselam P. Iacconi L. Btter-Jensen K. Atobe 《Radiation measurements》2004,38(4-6):615-618
Spectral properties of cubic boron nitride have been studied using methods of photoluminescence (PL), X-ray excited luminescence (XL), thermoluminescence (TL) and optically stimulated luminescence. It is found that emission of cubic boron nitride is presented by 4 subbands, their relative yield is determined by the excitation type: blue, green (dominant) and red bands are observed in PL, ultraviolet, blue (dominant), green and red bands—in XL. Three thermal peaks are found in TL curves in the 0–700°C temperature range, their presence and intensity depend on radiation type used. A tentative correspondence between thermal peaks and emission bands is found. 相似文献
945.
Ya. B. Soskovets A. Ya. Khairullina V. A. Babenko 《Journal of Applied Spectroscopy》2006,73(4):576-582
We have studied the luminescence of planar nanostructures based on amorphous copper, excited by a low-intensity source in
the UV region of the spectrum. We have shown that it is dependent on the packing density of copper granules on the surface
of the quartz substrate, the presence of chains of granules, the optical properties of the surrounding medium, and the oxidation
time. The observed maxima at the wavelengths of 400 nm and 520 nm correspond to luminescence of the quartz and copper oxide
Cu2O. The maximum at 650 nm is located in the region of plasma resonances of the oxidized copper chains and aggregates, and is
enhanced in the “hot spot” region near the surface of interacting copper particles.
__________
Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 73, No. 4, pp. 510–515, July–August, 2006. 相似文献
946.
We have studied the regular patterns of the change in the electronic transition frequency in low-temperature luminescence
spectra of uranyl trinitrate and tetranitrate crystals with alkali metal cations or an NH
4
+
group as the outer-sphere cations, as a function of the ionization potential of the latter. An analogous study was carried
out as a function of the ratio of the concentrations of impurity and matrix for different cations in mixed crystals and solid
solutions. Analysis of the results obtained, together with available crystallographic data, allowed us to propose a cluster
model for the uranyl complex. The observed regular patterns are also explained from the standpoint of statistical thermodynamics.
__________
Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 73, No. 5, pp. 588–591, September–October, 2006. 相似文献
947.
948.
D. V. Romanov N. V. Vasil’ev A. I. Lyamin N. P. Ivanovskaya N. S. Osinb 《Russian Chemical Bulletin》2006,55(2):276-280
The Claisen condensation of diesters of fluorinated dicarboxylic acids with 2-acetyl-naphthalene affords the corresponding
naphthyl-containing tetraketones and diketo esters. The luminescence-spectral properties and stability constants of complexes
of these compounds with Eu3+ ions were estimated. The characteristics of the complexes are comparable with those of fluorinated β-diketones containing
chromophoric substituents, which are widely used in luminescence analysis. The synthesized naphthyl-containing diketo esters
are efficiently conjugated with proteins and can be used for detection of biospecific interactions.
Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 2, pp. 269—273, February, 2006. 相似文献
949.
950.
稀土离子Er注入多孔硅中.在350keV能量,1×1012~1×1015/cm2剂量范围内,注入后的多孔硅仍保持明亮的可见光发射.退火后,在近红外区测到1.54μm附近Er3+的特征发射.其发射强度比硅单晶对照样品明显增强,实验表明这增强作用来源于多孔硅的表面发光层.电化学制备过程中在表面层中带入的O、C、F等多种杂质可能是Er3+发光增强的原因. 相似文献